1. Field of the Invention
The invention relates to retractors that are used in cardiovascular surgery and, more particularly, to a retractor that permits such operations to be conducted with reduced trauma to the patient.
2. Description of the Prior Art
In the course of such operative procedures as mitral valve surgery and mammary artery surgery, it is necessary to expose the heart. Such exposure traditionally has been accomplished by cutting an incision completely through the sternum and retracting the sternum. This procedure is known as a full sternotomy.
The retraction is accomplished by a retractor that employs parallel grips that engage the edges of the separated sternum. The grips are mounted on a toothed crossbar. One of the grips is fixed to one end of the crossbar, while the other grip is movably mounted to the crossbar by means of a pinion that engages the teeth of the crossbar. Upon rotating the pinion, the movable grip can be moved away from the fixed grip, thereby retracting the sternum so as to expose the heart. A retractor of the type described is shown in U.S. Re. 34,150, issued Dec. 29, 1992 to A. E. Santilli and D. M. Cosgrove III ("the '150 patent"), the disclosure of which is incorporated herein by reference.
After the sternum has been retracted, it is necessary to retract portions of the heart in order to expose diseased or defective parts thereof. Such retraction has been accomplished by attaching a cardiovascular retractor to one of the grips of the sternum retractor. The cardiovascular retractor, in preferred form, includes a horizontal rod to which retractor blades having elongate handles are attached by means of universal clamps. The rod is spaced above the grip a considerable distance in order to permit the blades to have access to the heart at a favorable angle. The blades can be moved so as to engage portions of the heart to be retracted. Thereafter, upon pulling the blades and locking them in place by tightening the universal clamps, the heart can be retracted in any manner desired and maintained in that position as long as necessary.
The blades in the described construction can be moved back and forth, up and down, side to side, and they can be pivoted about the longitudinal axis of the handle. Such versatility enables the device to be used for virtually any type of heart operation where retraction is required. A preferred example of the device in question is disclosed in the '150 patent.
While the retractor disclosed in the '150 patent is effective for retraction of the sternum and subsequent retraction of the heart, unfortunately the operative technique is very invasive. That is, the complete splitting of the sternum that occurs during a full sternotomy, coupled with retraction of the sternum, is an extremely traumatic procedure. The recovery time from such a procedure can be significant. Further, the patient will experience considerable pain and discomfort during the recovery process. It is possible that the trauma associated with the process can have a negative impact on the patient's recovery from the operation.
Desirably, a retractor would exist that would permit surgical procedures to be performed that are less invasive than are possible with presently available retractors. Preferably, any such less invasive retractor would be relatively small and lightweight compared with prior retractors.